RDFa, which stands for Resource Description Framework in attributes, is a W3C recommendation, which adds a set of attribute level extensions to XHTML for embedding rich metadata within web documents. While not everyone believes that W3C standards are incredibly necessary to operate a successful site, some see a great deal of potential for search engine optimization in RDFa.

In fact, this is the topic of a current WebProWorld thread, which was started by Dave Lauretti of MoreStar, who asks, "Are you working the RDFa Framework into your SEO campaigns?" He writes, "Now under certain conditions and with certain search strings on both Google and Yahoo we can find instances where the RDFa framework integrated within a website can enhance their listing in the search results."

Lauretti refers to an article from last summer at A List Apart, by Mark Birbeck who said that Google was beginning to process RDFa and Microformats as it indexes sites, using the parsed data to enhance the display of search results with "rich snippets". This results in the Google results you see like this:

"It's a simple change to the display of search results, yet our experiments have shown that users find the new data valuable -- if they see useful and relevant information from the page, they are more likely to click through," Google said upon the launch of rich snippets.

Google says it is experimenting with markup for business and location data, but that it doesn't currently display this information, unless the business or organization is part of a review (hence the results in the above example). But when review information is marked up in the body of a web page, Google can identify it and may make it available in search results. When review information is shown in search results, this can of course entice users to click through to the page (one of the many reasons to treat customers right and monitor your reputation).

Currently Google uses RDFa for reviews, but this search also displays the date of the review, the star rating, the author and the price range of an iPod, as Lauretti points out.

Best Buy's lead web development engineer reported that by adding RDFa the company saw improved ranking for respective pages. They saw a 30% increase in traffic, and Yahoo evidently observed a 15% increase in click-through rates.(via Steven Pemberton)

Implications for SEO

I'm not going to get into the technical side of RDFa here (see resources listed later in the article), but I would like to get into some of the implications that Google's use of RDFa could have on SEO practices. For one, rich snippets can show specific information related to products that are searched for. For example, a result for a movie search could bring up information like:

- Run time- Release Date- Rating- Theaters that are showing it

"The implementation of RDFa not only gives more information about products or services but also increases the visibility of these in the latest generations of search engines, recommender systems and other applications," Lauretti tells WebProNews. "If accuracy is an issue when it comes to search and search results then pages with RDFa will get better rankings as there would be little to question regarding the page theme." (Source) He provides the following chart containing examples of the types of data that could potentially be displayed with RDFa:

"It is obvious that search marketers and SEOs will be utilizing this ability for themselves and their clients," says Lauretti. Take contact information specifically. "Using RDFa in your contact information clarifies to the search engine that the text within your contact block of code is indeed contact information." He says in this same light, "people information" can be displayed in the search results (usually social networking info). You could potentially show manufacturer information or author information.RDFa actually has implications beyond just Google's regular web search. With respect to Google's Image search, the owner of images can also use RDFa to provide license information about the images they own. Google currently allows image searchers to have images displayed based on license type, and using RDFa with your images lets the search bots know under which licenses you are making your images available (Via Mark Birbeck). There is also RDFa support for video.

Following are some resources where you can learn more about RDFa and how to implement it:

Google's Matt Cutts has said in the past that Google has been kind of "white listing" sites to get rich snippets, as Google feels they are appropriate, but as they grow more confident that such snippets don't hurt the user experience, then Google will likely roll the ability out more and more broadly. This is one thing to keep an eye on as the year progresses, and is why those in the WebProWorld thread believe RDFa will become a bigger topic of discussion in 2010.